Clay-turning machine



L. LI RANDALL AND E. A. FRIES.

CLAY vHummm MAGHINE.`

APPLICATION FILED JUNE 12, i916.

Wm. WM. Nm. WVG k@ W L. L. RANDALL AND E. A. FRIES.

CLAY TURNING MACHINE.

APPLxCATIoN FILED 11111512, 1916.

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Patented Aug. 3, 1920.

L. L. RANDALL AND L. A. FALLS..

-CLAY TURNING MACHINE. APPLICATION FILED LUNE-12, |916.

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- Patented Aug. 3, 1920..

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LILLIAN L. RANDALL AND EDY/VAR@ A. FRIS, 0F BOSTON, MASSACHUSETTS.

^ CLAY-TURNING ilpraorriivr..

Specification of Letters Patent. Palgllged .Angg 3, 1920,`

Application filed .Tune 12, 1916. Serial No. 103,081.

To all whom t may concern Be it known that we, LTLLIAN L. RANDALL and EDWARD A. F runs, both citizens of the United States, and residents of Boston, in the county of Suffolk and State of Massachusetts, have invented new and useful 1mprovements in Clay-Turning Machines, of which the following is a speciiication.

This invention relates to a machine for turning articles from a bar or rod of plastic material, and moreparticularly for turning and forming such articles as spark plug bodies automatically from a bar or rodof clay. Heretofore the practice has been to turn such articles from spools or short lengths of clay and it has not been found practicable so far as we are aware successfully to form such articles from a bar of clay on account of they soft rand plastic nature of the material and the difliculty of handling it except in small units without breaking and destroying a very large percentage of the material. The object of the present invention is to produce a machine for turning and forming articles from the continuous clay bar that may be several feet in length, which will perform its various operations of cutting, forming and boring automatically and far more rapidly than has heretofore been possible in machines handling individual spools or short blanks, and which will do its work accurately and without danger of injury to the bar being operated upon.

In the accompanying drawings which illustrate a turning machine embodying the invention,-

Figure 1 is a side view, partly in section, of the machine; v

Fig. 2 is a plan view of the machine;

Fig. 3 is an end elevation viewed. from the right of Figs. 1 and 2;

Fig. 4 is an enlarged horizontal section showing in detail the hollow spindle which carries the bar of clay, and the forming, cutting and boring instruments; y

Fig. 5 is an enlarged detail showing the construction of the gripping collet at the end of the hollow spindle; and

. Fig. 6 is a longitudinally vertical section of parts of the step-by-step work feeding mechanism.

Referring to the drawings, B is the bedy plate of the machine upon which all ythe working parts are mounted. Upright standf ards 1, 2, 3, 4, 5 and 6 support the various parts as hereinafter more fully explained,l

the standards 4 and 5 constituting the main supporting frames between which the forming, cutting and boring` instruments are located. 7 is the main driving shaft, journaled in standards 2, 4 and 5, and takes its power from driving pulley 8 on a lshort shaft 9 mounted on suitable standards, andthence through gear l0 fast onshaft 9 and gear 11 fast on shaft 7. The driving pulley 8 is connected with any suitable source 'off power (not shown). n

rllhe center shaft l2 is journaled in standards 4, 5 and 6, and is rotated through gears'r 13 and 14 fixed respectively to shafts 7 and 12. A drill cam 15 for actuating the boring tool or drill, hereinafter described, is i'ixed to shaft 12 between standards 5 and G. The forming tool is actuated from shaft 12 through gear 14 fixed on shaft 12, gear 16, journaled on an idler shaft, gear 17 fixed on shaft 18, gear 17 a also fixed to shaft 18,

idler gear 19 mounted on shaft20, and gear 21 mounted on cam shaft 22, to which is fixed the cam 23 for reciprocating the forming tool. Shafts 18, 20 and 22 are supported between the upright standards 4 and 5.

.Y endwise by means of a shipper rod 30 connected to a ring 28, in which is a ball raceway 27 fixed to the hollow spindle, and ball bearings 29 between the raceway 27 and the ring 28, thereby allowing the spindle to turn freely within the shipping ring 28. The

shipper rod 30 is pivoted at its lower end Y to the bed plate B and is oscillated by means of a cam 32 against which a cam roller 3l runs, mounted on a suitable bracket on rod 30.

The forward end of the hollow spindle is provided with a collet 33, the end of which is divided by a series of slots 33a forming a plurality of resilient fingers or compressible jaw members adapted frictionally to engage the bar of clay or similar plastic material C. The bar of clay C ts loosely within the body ofthe hollow spindle 25 but is frictionally gripped at the forward4 end. by the resilient lingers of the collet 33 so as to rotate withgthe hollow spindle. `The exteriors of the fingers at the extremity of the collet33 are tapered so as to engage a clutch ring 34 which turns in ball bearings pressv the resilient,grippingfingers of the collet 33 into firm contact with the clay bar C, and also serves to hold the end of the colt let andthe clay bark gripped thereby accurately concentric with `the axis of the spindle, it being understood thatthe resilient gripping fingers if not thus supported and centered are sufficiently flexible to endanger the forwardmost end of the claybar, being deflected from the true axis of the spindle.

The forming tool 37, which as herein shown has a configuration adapted to shape one end `of the porcelain body of a spark plug,ismounted to slide forward and backward in aslideway 38 which is adjustable lengthwise of a crosshead 39 mountedon the top of standards 4 and 5. The forming tool 37 is actuated by the cam 23 which pushes the tool 37 forward, while a `spring 40 draws it back and holds the cam follower 38 against the face of cam 23. The forming tool- 3'T, as herein shown, ,is also provided with a projection which servesas a cutting off tool for the finished article A when the forming, cutting and boring operations are completed.

The cutting tool 4lat .thev opposite Vside of the work from the forming tool is fixed in a clamp 42, the latter being adjustably secured to a block 43which slides lengthwise of bar 44. A cam follower 45 secured to the bottom of block 43 engages thecam path in cam 24 by which the cutting tool 41 is reciprocated. The bar44may beadjusted on the standards 4 and 5, to various angles with relation to the work byrneans of slots and bolts 46 and 47, one ,pair at each end,

thereby determining vthe taper of the cut of l tool 41. It will be understood that the tool 4l cuts the tapered end of the porcelain body of a spark plug A. opposite the end shaped by the forming tool 37.

A drill or boring tool 4S for drilling a hole through the center of the spark plug body or other article being made is fixed to atool holder 49, which is rotatably mounted von ball vbearings 50, 50, in the forward end vof the hollow drill carrier 5l. The drill carrier 51 does not rotate but is mounted to slide lengthwisel in suitable bearings at the top of standards 5 and 6. The forward end of the carrier 51is square and is guided in a square way 54 at the top of standard 5. The carrier 5l is moved forward by the cam l5 and cam roller 52 secured `to the carrier 5l, and is moved backward by spring 53 between the upright 6 and a suitable collar on the rear end of carrier 5l.V

The tool holder 49 is normally heldagainst rotation by means of a clutch member mountedinside of the carrier 5l and having a clutch surface cooperating with a complemental clutch surface on the rear end of tool holder 49. The clutch member 55 is'held against rotation inthe carrier 5l by any suitd able means, such as a pin 56, extending from the carrier 5l into a suitable slot or groove in the stem of clutchmembcr A spring 5'? normally presses the clutch member forward into `engagement with the complementalyiclutch `surface on the end oftool holder 49, thereby holding the tool holder 49 normally against rotation. As the carrier 5l isimoved forward bv the cam l5 the tool and tool holder will be held fixed or non-rotatable until the latch 58, which is 55, arresting the latter', and pushing it out of engagement with the complementary clutch surface on the end of the tool holder 49. The tool holder and boring tool are now free to turn in the ball bearings 50 with the rotating clay bar, thereby preventing the friction be tween the boring tool and the clay from breaking the bar, and also acting as a rotating arbor to support the clay while theforming and cutting tools 37 and 4l are finishing their work.

The several tool-actuating cams are arranged, and timed so that the boring tool starts first, the cutting tool starts next and makes its complete travel forward before the mshed inward enfraoinfrthe clutch member f3 D b breakingofl", the drill will have traveled the full length of its stroke and have been released fromthe clntchmember 55 so that the boring tool will remain in the clay blank but will rotate therewith, thus stopping thel ward end of the push rod 62 to engage-the rear end kof the clay barand to rotate with the clay bar as `the latter turns with the rotary hollow spindle 25. The push rod 62 is held in projected position, as shown in Fig. 1, by, means of a removable pin 611 passing through slots in bar and rod 62. A series of notches 65 corresponding to the length of the successive forward feeding movements of the clay bar are provided in the top of bar 60 and are engaged successively by a spring-pressed latch 66 mounted in the slideway 61 at the top of vupright 2. The feed bar 60 and push rod 62 are advanced intermittently step by step-by means of a gear segment 6'?, which engages a rack 67a on the under side of bar 60. The gear segment 67 is fast on shaft 68, journaled in brackets mounted on upright 1, and a worm wheel 69 also fast on shaft 68 meshes into and is driven by a worm gear 70 fast on the end of driving shaft 7. At each rotation of the wormgear 69 and gear segment 67 the feed bar 60, push rod 62 and clay bar C will be advanced one step, or the distance of one notch 65. This step by step feeding device is so timed that the clay bar will be advanced after the completion of each operation of the cutting, forming and boring tools, and at the time when the clutch ring 34 at the forward end of the rotary spindle is released from the gripping fingers of the collet 33.

In order to insert a new clay bar C, the push rod 62 may be withdrawn from the rear end of the spindle 25 and pushed rearwardly through the bar 60 by removing the lock pin 6d. After thek clay bar C has been inserted in the hollow spindle 25, push rod 62 is again projected to the position shown in Fig. 1, and locked in projected position by means ofpin 64;. After the feed bar 60 has been moved forward its full length as above described, it may be returned to its initial position by hand by lifting the latch 66 out of the notches 65 and sliding the bar 60 rearwardly in its slideway I61.

In the machine above described the fragile and flexible clay bar C is supported throughout its whole 'length in the hollow. rotary spindle 25 with the exception of the short end projecting into vthe region of the working tools. 1t may thus .be given a very high y speed ofrotationy and is yfully protected against the danger of breaking. rlhe speed of operation and the rate of production yof the machine in forming `and cutting off the desired articles from the end of a continuous bar, are very much higher 'than has heretofore been possible in machines forming simi-` i .sufficiently firm grip .to rotate with the hollow spindle 25 without danger of breaking the rod 5. and the projecting end of the blank from which the articles are being formed is supported during the critical operation of the forming and cutting tools .by means of the boring tool which is released after the performance ofits boring function, so as to rotate with the work and afford a supporting arbor to reinforce the article against the ac-A tion of the forming and cutting tools.

During the retracting movement ofthe boring tool i8 after the turned article is completed, a stripping device 71, consisting of a finger or pair of fingers extending between the forward end of the tool holderif) and the nearest end of the finished artcle A, rand secured to the fixed slidway 54 engages the end of the finished article, pushing it off from the receding boring tool 4S, whereupon the finished article is dropped out of the machine i into asuitable chute or other receptacle (not show-n).

We claim:

1. A machine lfor turning plastic material comprising a` tube adapted to have an elongate rod4 of plastic material fed therethrough, the tube being arranged closely to confine the rod of plastic material throughout the entire length of the rod, means at the forward end of the tube yieldingly to grip said rod throughout an extensive area, a tool in operative relationship to the end of said rod projecting from the forward end of said tube, and means for producing relative angular motion between the tube and the tool .to cause the tool to operate upon they rod. Y

3. A machine for turning plastic material comprising a rotary tube adapted torhave an elongate rod of plastic material fedtherethrough, the tube being arranged closely to confine the rod of plastic material throughout the entire length of the rod, the forward end of the tube being slotted so as to form a plurality of yielding fingers of substantially the saine internal diameter as the tube and covering substantially the entire periphery.

of the rod at the forward end of the tube7 and means for rotating the tube so as to turn the end of said rod of plastic material projecting beyond the end of said tube. y

el. A turning machine of the character described comprising a hollow spindle along which bar of plastic material is adapted to be fed, means for gripping said bar. at the forward end of the spindle while the bar is being turned at its forward end, means for intermittently releasing the bar and stepping it forward, the latter meansincluding a push rod engaging the rearward. end of said bar and means for disengaging the push rod from the end of said bar `after the bar has been stepped forward. A turning machine of the character described comprising `a hollow spindle adapted to receive a bar of plastic mate-` rial, the forward en d of the spindle being provided with compressible means having an outer' surface tapered forwardly, a eollar surrounding the .compressible means' and having an inner surface` tapered forwardly so that the coinpressible means is caused to grip said bar when the spindle is moved forwardly, means for intermittently retracting the spindle to release said bar, and means for advancing the bar along the spindle while the spindle is'retracted, the latter means including a push `rod engaging the rearward end of said bar, said ar being carried forward out of engage-v ment with the push rod after each advancement by the spindle being moved forwardly into said collar.

G. A machine for turning plastic material comprising means for rotating a bar of plastic material, a boring tool, means for advancing the boring tool into said bar along' the axis ofrotation of the bar, and means for turning the exterior of the bar while the boringl tool `is extended thereinto, whereby the boring tool functions as an arbor to support the plastic material while it is being turned. Y

7. A turning machine of the character described comprising means' for rotating a` bar of plastic material, a boring tool,

means for advancing the boring tool into said bar along the axis of rotation of the bar, means for restraining'the boring tool from rotating until it has been advanced a predetermined distance into the bar and then releasing it so that it may rotate with the bar, andmeans for turning the exterior of the barfwhile the boring tool is extended thereinto, whereby the `boring tool functions as anarbor to support the plastic ma terial while it is being turned.

S. A Vturning' machine .of the character described comprising means for rotating aturned.

9. A machine for turning plastic material eomirising a hollow'sp'indle adapted to hold and support a bar of plastic material to be operated upon, means to rotate the hollow spindle, a push rod extending into the rear end of the hollow spindle having a rotary head, and means to actuate said push rod to advance said bar through said hollow spindle l()` Aturning machine of the character described comprising means to support and rotate the blank to be operated upon, a boring tool carrier, means to move said carrier toward and away from the blank support-` ing means, a boring tool rotatable in said carrier, means normally to hold said boring tool against rotation, and means actu-` ated at a predetermined point in the move ment of the carrier to release the Vtool so as to permit it to rotate. l

1l. A turning machine of the character described comprising a hollow spindle adapted to hold and support a bar of plastic material to loe operated upon, means to rotate the hollow spindle, a boring tool carrier, means to move said carrier toward and away from the hollow spindle, a boring tool` rotatable in said carrier, Vmean normally to hold said boring tool against rotation, and means actuated at a predetermined point inthe forward movement of the carrier to release thetool and permit the same to rotate with the work. i

12. In a machine of' the `character described, a hollow tool carrier, means to re 'ciprocate said carrier, a tool holder rotatable in said carrier having a clutch member at its inner end, a complementary clutch member movable lengthwise in said carrier normally engaging the clutch member on `the tool'lholder, and a' stop adapted to arrest said lengthwise movable clutch member and disengage the saine fromth'e tool holder ata predetermined point inV the forward movement of the/carrier, thereby releasing the tool holder so as to permit it to rotate. 13. The method of forming tubular articles from plastic material comprising rotat- 5 ing a blank of the plastic material, boring the blank along` its axis of rotation, and turning the exterior of the blank While the boring tool is extended thereinto, the plastic blank being supported by the boring tool While being turned. c 10 'Signed by us at Boston, Massachusetts,

' this seventh day of June, 1916.

-LILLIAN L. RANDALL.

EDVARD A. FRIES. 

